I. Field of the Invention
The present invention relates generally to mobile systems for mixing and dispensing concrete and, more particularly, to a lightweight discharge chute assembly for offloading concrete mobile systems which includes a plurality of sections that are readily handled for assembly and disassembly and which have integral nesting/stacking features which enable stable compact storage and shipping configurations. The discharge chute assembly is also useful for offloading a variety of other materials and is adaptable for use with other concrete mixing and dispensing systems such as barge-mounted or stationary concrete mixers.
II. Related Art
Transit or mobile concrete mixing trucks which carry large mixing drums are well known and have been used extensively in the construction industry for preparing and transporting concrete to job-site locations and discharging the concrete into forms or containers for further transport. An important part of this operation involves the discharging of concrete from the mixing drum into the forms, other molding structures or other transporting containers. In this regard, most mixing trucks are equipped with a side-to-side pivoting main discharge chute section which is located beneath a charge/discharge opening at one end of the drum. The discharge chute further normally contains a pivotally connected second chute section which folds out from the main chute section attached thereto by hinges. Additional chute sections have been carried on such trucks which can be hooked together and onto the end of the hinged second chute section to provide variations in the length of the discharge chute as needed.
The chute extension sections have traditionally been fabricated from heavy gauge steel in order to withstand the cantilevered stresses associated with carrying amounts of heavy concrete mix. Such metal chute components, however, are heavy for operators to handle, may tend to corrode and are subject to abrasive wear which results in roughened surfaces which further impair efficiency. Additionally, the steel extension chutes wear thin and become weak from the abrasion. Steel chutes are also subject to corrosion and scaling.
Non-metal chute components are shown, for example, in U.S. Pat. No. 5,056,641 to Loefke et al, assigned to the same assignee as the present invention and which is incorporated herein by reference for any purpose. These sectional components feature a multi-ribbed polymer construction and are releasably joined together using a hinge-type projection and socket system with an associated rotating cam locking arrangement. While this system is met with a certain amount of success, there has remained a need for a multi-section concrete discharge chute arrangement that is not only even lighter in weight, less expensive and smooth-surfaced, but one in which the sections are more easily handled by workers and one which simplifies the reinforced construction of the chute sections. In addition, it would be desirable that the sections of the multi-section arrangement be configured to interlock in a nesting/stacking configuration such that the disassembled system is more stable and convenient to store and ship.